Impact of enteral protein supplementation in premature infants

David M Barrus1, Joann Romano-Keeler2, Christopher Carr3, Kira Segebarth4, Betty Claxton2, William F Walsh2, Paul J Flakoll51Department of Neonatology, Saint Francis Hospital–Bartlett, Memphis, TN, 2Department of Pediatrics, Vanderbilt Medical Center, Nashville, TN, 3Department of Surgery, Naval Hospital Bremerton, Bremerton, WA, 4Pediatric and Diabetes Specialists, Carolinas Medical Center, Charlotte, NC, 5Department of Surgery, Vanderbilt Medical Center, Nashville, TN, USAObjective: The quantity of enteral protein supplementation required by premature infants to optimize growth has not been determined. This study compares the growth of premature infants fed the current standard intake of protein (3.5 g/kg/day) with the growth of those fed a higher amount (4.0 g/kg/day).Study design: Fifty-two infants <1500 g and <33 weeks gestational age participated in a blinded, single-center, prospective randomized control trial to compare growth between two groups of different protein-intake levels. Primary outcomes were average daily weight gain (g/kg/day), head-circumference (cm/kg/week) and linear growth velocity (cm/kg/week). Secondary outcomes were serum indices of protein tolerance and plasma amino acid concentrations.Results: Infants receiving higher amounts of protein had higher rates of growth for body weight (18.2 ± 0.7 versus 16.2 ± 1.0 g/kg/day; P < 0.05) and head circumference (0.87 ± 0.08 versus 0.62 ± 0.07 cm/kg/week; P < 0.05), with no differences in blood protein or plasma amino acid concentrations. Length of hospital stay was 14 days shorter for the higher-protein group (51.4 ± 4.0 versus 65.9 ± 6.3 days).Conclusion: Increasing premature infant enteral protein supplementation from a calculated intake of 3.5–4.0 g/kg/day improved growth in a safe manner.Keywords: human milk, human milk fortifier, growth, low birth weigh

Barriers to enrollment in a randomized controlled trial of hydrocortisone for cardiovascular insufficiency in term and late preterm newborn infants.

ObjectiveTo analyze reasons for low enrollment in a randomized controlled trial (RCT) of the effect of hydrocortisone for cardiovascular insufficiency on survival without neurodevelopmental impairment (NDI) in term/late preterm newborns.Study designThe original study was a multicenter RCT. Eligibility: ⩾34 weeks' gestation, <72 h old, mechanically ventilated, receiving inotrope. Primary outcome was NDI at 2 years; infants with diagnoses at high risk for NDI were excluded. This paper presents an analysis of reasons for low patient enrollment.ResultsTwo hundred and fifty-seven of the 932 otherwise eligible infants received inotropes; however, 207 (81%) had exclusionary diagnoses. Only 12 infants were randomized over 10 months; therefore, the study was terminated. Contributing factors included few eligible infants after exclusions, open-label steroid therapy and a narrow enrollment window.ConclusionDespite an observational study to estimate the population, very few infants were enrolled. Successful RCTs of emergent therapy may require fewer exclusions, a short-term primary outcome, waiver of consent and/or other alternatives

Documenting the NICU design dilemma: parent and staff perceptions of open ward versus single family room units

Objective: With neonatal intensive care units (NICUs) evolving from multipatient wards toward family-friendly, single-family room units, the study objective was to compare satisfaction levels of families and health-care staff across these differing NICU facility designs. Study Design: This prospective study documented, by means of institutional review board-approved questionnaire survey protocols, the perceptions of parents and staff from two contrasting NICU environments. Result: Findings showed that demographic subgroups of parents and staff perceived the advantages and disadvantages of the two facility designs differently. Staff perceptions varied with previous experience, acclimation time and employment position, whereas parental perceptions revealed a naiveté bias through surveys of transitional parents with experience in both NICU facilities. Conclusion: Use of transitional parent surveys showed a subject naiveté bias inherent in perceptions of inexperienced parents. Grouping all survey participants demographically provided more informative interpretations of data, and revealed staff perceptions to vary with position, previous training and hospital experience

Quantifying the efficiency of hydroxyapatite mineralising peptides

We present a non-destructive analytical calibration tool to allow quantitative assessment of individual calcium phosphates such as hydroxyapatite (HAP) from mixtures including brushite. Many experimental approaches are used to evaluate the mineralising capabilities of biomolecules including peptides. However, it is difficult to quantitatively compare the efficacy of peptides in the promotion of mineralisation when inseparable mixtures of different minerals are produced. To address this challenge, a series of hydroxyapatite and brushite mixtures were produced as a percent/weight (0–100%) from pure components and multiple (N=10) XRD patterns were collected for each mixture. A linear relationship between the ratio of selected peak heights and the molar ratio was found. Using this method, the mineralising capabilities of three known hydroxyapatite binding peptides, CaP(S) STLPIPHEFSRE, CaP(V) VTKHLNQISQSY and CaP(H) SVSVGMKPSPRP, was compared. All three directed mineralisation towards hydroxyapatite in a peptide concentration dependent manner. CaP(V) was most effective at inducing hydroxyapatite formation at higher reagent levels (Ca2+ = 200mM), as also seen with peptide-silk chimeric materials, whereas CaP(S) was most effective when lower concentrations of calcium (20mM) and phosphate were used. The approach can be extended to investigate HAP mineralisation in the presence of any number of mineralisation promoters or inhibitors

Treatment of Canine Osseous Tumors with Photodynamic Therapy: A Pilot Study

Photodynamic therapy uses nonthermal coherent light delivered via fiber optic cable to locally activate a photosensitive chemotherapeutic agent that ablates tumor tissue. Owing to the limitations of light penetration, it is unknown whether photodynamic therapy can treat large osseous tumors. We determined whether photodynamic therapy can induce necrosis in large osseous tumors, and if so, to quantify the volume of treated tissue. In a pilot study we treated seven dogs with spontaneous osteosarcomas of the distal radius. Tumors were imaged with MRI before and 48 hours after treatment, and the volumes of hypointense regions were compared. The treated limbs were amputated immediately after imaging at 48 hours and sectioned corresponding to the MR axial images. We identified tumor necrosis histologically; the regions of necrosis corresponded anatomically to hypointense tissue on MRI. The mean volume of necrotic tissue seen on MRI after photodynamic therapy was 21,305 mm3 compared with a pretreatment volume of 6108 mm3. These pilot data suggest photodynamic therapy penetrates relatively large canine osseous tumors and may be a useful adjunct for treatment of bone tumors

Cohesive forces prevent the rotational breakup of rubble-pile asteroid (29075) 1950 DA

Space missions and ground-based observations have shown that some asteroids are loose collections of rubble rather than solid bodies. The physical behaviour of such ‘rubble-pile’ asteroids has been traditionally described using only gravitational and frictional forces within a granular material. Cohesive forces in the form of small van der Waals forces between constituent grains have recently been predicted to be important for small rubble piles (ten kilometres across or less), and could potentially explain fast rotation rates in the small-asteroid population. The strongest evidence so far has come from an analysis of the rotational breakup of the main-belt comet P/2013 R3, although that was indirect and poorly constrained by observations. Here we report that the kilometre-sized asteroid (29075) 1950 DA is a rubble pile that is rotating faster than is allowed by gravity and friction. We find that cohesive forces are required to prevent surface mass shedding and structural failure, and that the strengths of the forces are comparable to, though somewhat less than, the forces found between the grains of lunar regolith

The Main Belt Comets and ice in the Solar System

We review the evidence for buried ice in the asteroid belt; specifically the questions around the so-called Main Belt Comets (MBCs). We summarise the evidence for water throughout the Solar System, and describe the various methods for detecting it, including remote sensing from ultraviolet to radio wavelengths. We review progress in the first decade of study of MBCs, including observations, modelling of ice survival, and discussion on their origins. We then look at which methods will likely be most effective for further progress, including the key challenge of direct detection of (escaping) water in these bodies